I have a 1949 3600 with a 235 6cyl. I had valve job done on the head. In the process of putting it all back together we've noticed a .005-.010" gap between the exhaust manifold and the head on one of the ports. I had the manifold re-ground but it didn't improve the fit. Is the gap a problem? Any suggestions on fixing it?

Thanks for the help!
Dierks321